A brief look at the famous emerald and alexandrite from Russia's Ural Mountain mines.

The use of high-temperature lattice-diffusion heat treatment with beryllium to lighten the color of blue sapphires.

Do men and women have the same ability to see red? The answer might shock you.

In search of ruby and sapphire on the lost Isle of Madagascar.

A discussion of how inclusion patterns mimic crystallographic symmetry in ruby and sapphire.

Introducing the blue filter as a gemological tool to separate natural and Verneuil synthetic yellow sapphires.

Virtually all gemologists are aware of the curved growth lines and gas bubbles in Verneuil (flame-fusion) synthetic corundum, but few understand exactly why they occur and how they are distributed in these stones. This article clarifies these important identifying features.